Over the past several years, the medical profession has been extremely concerned about exposure of medical personnel to patients and fluid samples infected with communicable diseases, and particularly AIDS. In an effort to minimize the risk of infection, medical personnel have donned masks, gloves and other protective devices in the treatment of patients.
One of the ways in which medical personnel can be subjected to a communicable disease is through the handling of devices which are designed to inject or withdraw a fluid from a patient (e.g., a hypodermic syringe, and the like). Once the syringe is contacted with the patients blood through the injection process, it becomes a high-risk potential carrier of infectious disease.
Accordingly, the medical profession has recognized the need for a convenient and efficient means of protecting medical personnel from contaminated needles. One of the first major advancements in this area was the development of the disposable syringe.
The most common disposable syringe contains a fluid-containing barrel and a movable plunger therein. The top end of the barrel has a collar having an open ended cavity with grooves for removably securing therein a needle assembly. The needle assembly includes a rigidly fixed needle mounted in a base which is screwed into the cavity of the collar. The needle is covered with an elongated snap-on cap which is removed prior to use. In order to operate the syringe, a suitable needle assembly with the cap in place is twisted onto the collar of the syringe. The cap is removed and the needle is ready to be injected into the patient. After use, the cap is held in one hand and the needle assembly in the other hand. The user must then carefully place the cap over the needle and push downward until the cap snaps in place. The entire syringe may then be discarded. Such syringe devices enable a barrel to be used interchangeably with any size needle since the barrels and needle assemblies are typically packaged separately.
Despite the reduction in handling time, such disposable syringes have not allayed the concerns of the medical profession regarding the risk of infection by an exposed contaminated needle. This is because the elongated cap must be slowly and very carefully secured over the exposed needle thereby requiring complete concentration by the user.
In the often hectic and sometimes frantic performance of medical services, the user of such hypodermic needles often misaligns the cap and needle leading to needle pricks of the hand or arms. Such accidents occur because it is difficult to cover the needle properly under typical medical facility conditions. Accordingly, there have been efforts to provide a convenient and efficient means of covering contaminated needles to prevent post-use needle pricks.
Such efforts have focused on two methods of covering the needle. The first is to employ a cover which can be moved upwardly and over the needle and the second is to retract the needle within the barrel of the syringe. The use of a cover is exemplified by Sampson et al., U.S. Pat. No. 4,425,120; Mitchell, U.S. Pat. No. 4,631,057; Strauss, U.S. Pat. No. 4,664,645; and Fox, U.S. Pat. No. 4,695,274.
Syringe devices of the second type employing means for retracting the needle into the body of the syringe are shown in Vining et al., U.S. Pat. No. 4,507,117, Jagger et al., U.S. Pat. No. 4,592,744, DeLuccia, U.S. Pat. No. 4,675,005 and Haber et al U.S. Pat. No. 4,710,170.
The aforementioned devices have not gained commercial acceptance because they are complicated, difficult to manufacture and/or require substantial redesigning of the previously described standard syringe. More specifically, some such devices have a prepacked needle of a particular size which is loaded from within the barrel. As a result, the needle assemblies are not interchangeable with the standard barrel which adds to the cost of the syringe and makes the syringe less efficient to use. Furthermore, some of the prior devices do not permit external loading of the needle assembly on the top exterior surface of the barrel which also adds to the cost of the syringe.
Commercial efforts at capping contaminated needles have essentially rejected the complex and costly devices disclosed by the aforementioned patents. Instead, hospitals, clinics and individual medical practitioners have opted for systems which remove and store contaminated needles using devices which are separate and apart from the syringe itself.
One such device is sold under the trademark Vacusafe and includes a container for storing contaminated needles. The top of the container has a V-shaped hole with a serrated or gripping side that grips the needle assembly placed therein and dislodges it from the syringe when the syringe is rotated by the user.
Another such device is sold under the trademark Destructoclip which is similar to Vacusafe but has the added feature of cutting off the tip of the needle while the syringe is held in the hole in the top of the container.
While these systems are effective once the syringe is inserted through the opening of the device, they are disadvantageous because the contaminated needle must be moved in its exposed condition from the patient to the place where the storage container is located. Thus, the contaminated needle is exposed for an unacceptable period of time during which the risk of accidental contact with the user, the patient or other personnel is high.
It is therefore an object of the invention to provide a convenient and effective manner of promptly covering contaminated parts of a fluid passing device.
It is a further object of the invention to provide a disposable syringe in which a contaminated needle is promptly removed from any possible detrimental contact with the user, the patient or other personnel.
It is a still further object of the invention to provide a means of covering the needle of a disposable syringe of the type in which the needles and barrels are interchangeable.
It is another object of the invention to provide a disposable syringe in which the needle assembly is covered by a cap activated from a location which is remote from the contaminated needle tip.
It is another object of the invention to provide a disposable syringe in which the contaminated needle assembly is retracted into the barrel of the syringe from a location which is remote from the contaminated needle tip.
It is a still further object of the invention to provide a disposable syringe in which the used needed is prevented from reentering the aperture of the needle assembly.